Distribution of aflatoxins in tissues of growing pigs fed an aflatoxin-contaminated diet amended with a high affinity aluminosilicate sorbent

The effect of hydrated sodium calcium aluminosilicate (HSCAS) added to the diet of swine fed an aflatoxin-contaminated diet on tissue aflatoxin levels was investigated. Pigs were fed control (less than 10 ng/g B1 + B2), contaminated (500-600 ng/g B1 + B2), and contaminated +0.5% HSCAS diets. Tissues analyzed for the presence of aflatoxin B1, B2, and M1 residues included liver, muscle, kidney, and adipose. Addition of HSCAS to the contaminated diet significantly reduced the amount of M1 in liver, kidney, and muscle tissue. Aflatoxin B1 was not reduced in liver or kidney, but was decreased in muscle.     

Characterization of a high affinity piretanide receptor on kidney membranes

The tritiated loop diuretic, piretanide, is a useful ligand for specific diuretic receptors which are present in the plasma membranes of renal medullary cells. Its high specific activity (30 Ci X mmol-1) made it possible to demonstrate the existence of a high affinity receptor (Kd approximately 5 nM) and a binding site with low affinity. High affinity binding is saturable, reversible and displaceable by a number of non-radioactive loop diuretics. Structural analogues, devoid of diuretic activity, do not displace piretanide binding. No specific binding occurs in liver or spleen membranes.     

An outbreak of aflatoxicosis in Angora rabbits

An outbreak of aflatoxicosis in Angora rabbits involving a large number of rabbitries was investigated. Mortality was more in weaners than in adults. Affected animals showed anorexia, dullness and weight loss followed by jaundice in terminal stages. Death occurred within 3-4 d of the appearance of clinical signs. Livers were moderately to severely congested, icteric and were hard to cut. Gall bladders were distended and had inspissated bile. Liver sections showed degenerative changes of hepatic cells along with dilatation and engorgement of sinusoids. Bile ducts had mild to severe periportal fibrosis. Focal areas of pseudolobulation and regenerative foci were also predominant. The level of aflatoxin B1 in feed samples from various farms submitted at the time of the investigation varied from 90 to 540 ug aflatoxin B1/kg of feed. Withdrawal of feed and supplementary therapy resulted in gradual disappearance of signs and mortality.     

大剂量氨溴索预防早产儿肺透明膜病疗效分析

目的:探讨大剂量氨溴索预防早产儿肺透明膜病(HMD)的疗效。方法:将126例发生肺透明膜病早产儿分为预防组和对照组,对照组58例给予常规治疗,预防组68例在常规治疗的基础上应用氨溴索,观察两组早产儿肺透明膜病及并发症的发生率,监测入院6 h血气分析结果并进行比较。结果:对照组和预防组HMD的发生率(χ2=6.54,P<0.05)、入院6 h血气分析结果(P<0.05)、并发症发生率(P<0.05)比较差异均有统计学意义。结论:早期应用大剂量氨溴索预防早产儿肺透明膜病有较好疗效,适合基层医院推广应用。     

大剂量氨溴索预防早产儿肺透明膜病疗效分析

目的：探讨大剂量氨溴索预防早产儿肺透明膜病（HMD）的疗效。方法：将126例发生肺透明膜病早产儿分为预防组和对熙组，对照组58例给予常规治疗，预防组68例在常规治疗的基础上应用氨溴索，观察两组早产儿肺透明膜病及并发症的发生率，监测入院6h血气分析结果并进行比较。结果：对照组和预防组HMD的发生率（Χ^2=6．54，P〈0．05）、入院6h血气分析结果（P〈0．05）、并发症发生率（P〈0．05）比较差异均有统计学意义。结论：早期应用大剂量氨溴索预防早产儿肺透明膜病有较好疗效，适合基层医院推广应用。     

Effect of cellular desialylation on choline high affinity uptake and ecto-acetylcholinesterase activity of cholinergic neuroblasts.

It is not definitely established whether choline can be synthesized by nerve tissue (1,2). Its uptake by the neuronal membrane may be an important regulator of neuronal phosphatidylcholine and acetylcholine metabolism. An energy-dependent component of the choline uptake system has recently been found in neuroblastoma cell cultures (3). Choline uptake in cholinergic neuroblasts is markedly reduced by inhibition of cholinesterase activity (4). Further information about the system for choline transport still is lacking.To gain insight into the biochemical mechanism(s) at the cell surface which are involved in choline uptake by nerve cells, cultured cholinergic neuroblasts in the present study were subjected to gentle sialidase treatment, and choline uptake and acetylcholinesterase activities (AChE, EC 3.1.1.7) were determined in parallel. Removal of a portion of the cell surface sialic acid markedly reduced choline uptake and concurrently enhanced AChE activity. These findings suggest an interrelatedness of choline uptake and acetylcholinesterase activity mediated by sialic acid components in the outer surface of the cell.     

Investigations in the use of mice exposed to mycotoxins as a model for growing pigs.

A series of experiments was conducted to determine the feasibility of using mice to screen for possible dietary mycotoxin interactions before testing them with swine. Selected mycotoxins, deoxynivalenol (DON) and T-2 toxin, were fed to young mice, alone and in combination. The severity of effects on body weights caused by DON (0-20 mg DON/kg diet) was more pronounced in a dose-related manner when the animals were exposed to contaminated diets starting at 21 d of age than at 28 d (Experiment 1) as reflected in the analysis of variance. The relative variance among diets after 7 d was twice as great for the younger than for the older mice. In both age groups, the weight gain response was linear, similar to that seen in growing swine. In Experiment 2, a significant (p < .05) diet type x DON interaction for food consumption evident after 7 d, indicated that the effect of DON depended on the type of diet (freeze-dried vs. regular mash). There was no difference in food efficiency between diet type, but a strong dose-dependent effect due to DON was observed. When DON and T-2 toxin were fed together to young mice, a significant (p < .001) linear decrease in weight gain and food consumption was observed after 7 d on the contaminated diet as the toxin concentration increased.     

喹诺酮类药物对豚鼠心电图的影响

目的　观察比较环丙沙星、左氧氟沙星和司帕沙星的心脏毒性。方法　记录腹腔给药后豚鼠心电图 ,探讨对心电图各项指标的影响。结果　环丙沙星、左氧氟沙星及司帕沙星均能引起豚鼠心电图异常 ,出现 QT间期显著延长、室性早搏、房室传导阻滞等 ,而其他指标未见显著改变。在同等剂量下 ,左氧氟沙星对心电图影响最小 ,环丙沙星与左氧氟沙星接近 ,而司帕沙星而对心电图影响最大。结论　环丙沙星、左氧氟沙星及司帕沙星均可引起豚鼠心电图改变 ,但左氧氟沙星及环丙沙星的作用低于司帕沙星。     

affibody分子：一类具有高度亲和力的新配体

affibody分子是一类新的由58个氨基酸残基组成、相对分子质量约为6.5×103的亲和性配体,其功能类似于抗体却又有着一些抗体所不具备的性质,如相对分子质量小、折叠速率快、选择性和亲和力高,以及结构稳定,可耐受化学修饰等,因此被称为＂人工抗体＂。近年来affibody分子在生物科学的许多领域中得到广泛应用,本文综述了affibody分子的起源、特点及其在影像诊断和治疗学方面的研究进展和应用现状,并对其在药物载体方面的应用前景进行了展望。     

Effect of the enteric sorbent noolit on the psychoemotional status in mice]

The enterosorbent noolit (representing a mineral matrix base with immobilized lithium and silicon compounds) significantly affects the psychoemotional state of mice with depression model induced by prolonged social emotional stress. Noolit administration produces a pronounced anxiolytic and antidepressant effect and reduced the level of behavioral deficiency in the test animals.     

Intracelluar dynamics of a high affinity NGF receptor TrkA in PC12 cell

A high affinity nerve growth factor (NGF) receptor, tropomyosin-receptor kinase (TrkA), is visualized by expression of TrkA conjugated with cyan fluorescent protein (CFP) in PC12 cells. TrkA was distributed on the plasma membrane of PC12 cells almost uniformly in both differentiated cells and undifferentiated cells. NGF induced differentiation of PC12 cells transfected with TrkA-CFP normally as wild cells without transfection and the expression of TrkA was observed on the entire cell membrane which surrounds the cell body, axons and growth cones. Interestingly, TrkA-CFP was also present on the membrane of filopodia sticking out from the axon and growth cone. In the axonal region, transporting vesicles of TrkA with diameters ranging from 0.5 to 1.5 microm were observed. Some of these vesicles showed net directional movement along the axon in both directions, anterograde and retrograde. The mean velocity of anterograde and retrograde transport was 0.2+/-0.03 and 0.3+/-0.05 microm/s (mean+/-S.E.), respectively. Some vesicles moving anterogradely changed their direction occasionally although the net transport was anterograde. On the other hand, vesicles moving retrogradely seldom switched their direction in spite of occasional stops. These results demonstrated that the behavior of TrkA transporting vesicles in axons of PC12 cells was similar to that observed in the primary culture of sympathetic or sensory neuron. Therefore, it is suggested that the PC12 cell transfected with fluorescent protein-conjugated TrkA is a useful model for studying the signal transduction of NGF.     

Hydrated sodium calcium aluminosilicate (HSCAS), acidic HSCAS,and activated charcoal reduce urinary excretion of aflatoxin M1 in turkey poults. Lack of effect by activated charcoal on aflatoxicosis

In one experiment, the effect of inorganic sorbents on the metabolic fate of aflatoxin B₁ (AFB₁) was studied in turkey poults. At 5 weeks of age, female poults were surgically colostomized and 9 days later orally dosed with 0.75 mg AFB₁/kg BW. Hydrated sodium calcium aluminosilicate (HSCAS), acidic HSCAS, and activated charcoal (AC) were tested, by concomitant administration with AFB₁. Urine was collected up to 48 h post-dosing and analyzed for aflatoxin M₁ (AFM₁) which was the major metabolite found in all treatment groups. Hydrated sodium calcium aluminosilicate, previously proven beneficial in alleviating aflatoxicosis in farm animals, reduced urinary AFM₁ output when orally dosed simultaneous with AFB₁. Also, acidic HSCAS and AC significantly decreased AFM₁ excretion when administered concomitantly with AFB₁. A second experiment was conducted to evaluate the ability of two types of AC to modify aflatoxicosis when added to aflatoxin (AF)-contaminated (from culture material) diets of turkey poults. Although AC was able to decrease AFM₁ excretion in the first experiment, no protective effects from AF toxicity were observed in the feeding study.     

Identification of a novel high affinity adenosine binding protein from bovine striatum

Summary In solubilized extracts from bovine striatal membranes three different binding sites for 5-N-ethylcarboxamidoadenosine ([³H]NECA) were observed after separation of the extract by gel filtration on Sepharose CL-6B. The first peak was eluted in the void volume and contained the AZ adenosine receptor. In the second peak, [³H]NECA binding sites were eluted with a pharmacological profile characteristic of adenotin, a low affinity non-receptor adenosine binding protein. The third peak represented approximately 50% of the [³H]NECA binding activity. This site bound [³H]NECA in a reversible and saturable manner with K _D of 17 nmol/l and a binding capacity of 11.3 pmol/mg protein. In competition experiments, adenosine, NECA, NAD, nnosine, 5-AMP and S-adenosyl-L-homocysteine were the most potent ligands. In contrast to adenosine receptors, this site did neither bind adenosine receptor antagonists nor the A₂ selective agonist CGS 21,680 (2-[p-(2-carboxyethyl)phenethylamino]5-N-ethylcarboxamidoadenosine). These results suggest the existence of a novel high affinity binding site for adenosine of unknown function in bovine striatum.Abbreviations AMPPCP ,-methyleneadenosine-5-triphosphonate - CCPA 2-chloro-N⁶-cyclopentyladenosine - CHAPS 3-[3-(cholamidopropyl)dimethylammonio]-1-propanesulfonate - CGS 21,680 2-[p-(2-carboxyethyl)phenethylamino]-5-N-ethylcarbox-amidoadenosine - CPA N⁶-cyclopentyladenosine - DPCPX 1,3-dipropyl-8-cyclopentylxanthine - GppNHp guanosine-5-[,-imido]triphosphate - GTP[S] guanosine-5-O-(3-thiotriphosphate) - NBTI S-4-nitrobenzyl-6-thioinosine - NECA 5-N-ethylcarbox-amidoadenosine - NECG 5-N-ethylcarboxamidoguanosine - PIA N⁶-phenylisopropyladenosine - SAH S-adenosyl-L-homocysteine - XAC 8-{4-[([{(2-aminoethyl)-amino}carbonyl]-methyl)oxy]-phenyl}-1,3-dipropylxanthine Send offprint requests to A. Lorenzen at the above address     

槐果碱对哇巴因诱发豚鼠室性心律失常的影响

目的观察槐果碱的抗室性心律失常作用。方法将哇巴因诱发的室性心律失常豚鼠,分为对照组与不同剂量槐果碱组(5、2.5和1.25 mg·kg~(-1))。通过心电图仪连续观察记录室性早搏(室早)、室性心动过速(室速)、室扑、室颤及心脏停搏出现时间,计算哇巴因的累积量。结果槐果碱各组与对照组相比,仅5 mg·kg~(-1)组能增加出现室早、室速、室扑、室颤及心脏停搏的哇巴因累积量(P<0.01)。结论槐果碱对哇巴因诱发的豚鼠室性心律失常有一定的抑制作用,以5 mg·kg~(-1)的剂量为佳。